Abstract
F22, a low alloy steel, has become widely used in oil field production systems. However, current scale inhibitor technologies on the market often cause severe corrosion on F22, particularly at high temperature conditions. Therefore, F22 compatible scale inhibitors are in demand in the oil and gas industry. A F22 compatible scale inhibitor is required to be only mildly corrosive on F22, with a general corrosion rate of ≤ 4 mpy and no pitting corrosion, while maintaining high scale inhibition efficiency with a low minimum inhibitor concentration (MIC). A wide range of scale inhibitor products were evaluated for F22 corrosion rates in inhibitor compatibility testing and scale inhibition in dynamic tube-blocking (DTB) testing. The test temperature was as high as 240 °F (116 °C), and the test brine had positive saturation indices for calcium carbonate (CaCO3) and iron carbonate (FeCO3) scales. Based on the performance of both F22 compatibility and scale inhibition, the best blend was selected for further evaluation, i.e., subsea certification. Finally, the developed product has met all the requirements of a F22 compatible scale inhibitor, and has gone through a successful field trial, and it is ready for larger scale applications.
